package org.apache.maven.rtinfo.internal;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.apache.maven.rtinfo.RuntimeInformation;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;
import org.codehaus.plexus.logging.Logger;
import org.codehaus.plexus.util.IOUtil;
import org.codehaus.plexus.util.StringUtils;
import org.eclipse.aether.util.version.GenericVersionScheme;
import org.eclipse.aether.version.InvalidVersionSpecificationException;
import org.eclipse.aether.version.Version;
import org.eclipse.aether.version.VersionConstraint;
import org.eclipse.aether.version.VersionScheme;

/**
 * Provides information about the current Maven runtime.
 */
@Component(role = RuntimeInformation.class)
public class DefaultRuntimeInformation implements RuntimeInformation {

  @Requirement
  private Logger logger;

  private String mavenVersion;

  public String getMavenVersion() {
    if (mavenVersion == null) {
      Properties props = new Properties();

      String resource = "META-INF/maven/org.apache.maven/maven-core/pom.properties";

      InputStream is = DefaultRuntimeInformation.class.getResourceAsStream("/" + resource);
      if (is != null) {
        try {
          props.load(is);
        } catch (IOException e) {
          String msg = "Could not parse " + resource + ", Maven runtime information not available";
          if (logger.isDebugEnabled()) {
            logger.warn(msg, e);
          } else {
            logger.warn(msg);
          }
        } finally {
          IOUtil.close(is);
        }
      } else {
        logger.warn("Could not locate " + resource + " on classpath, Maven runtime information not available");
      }

      String version = props.getProperty("version", "").trim();

      if (!version.startsWith("${")) {
        mavenVersion = version;
      } else {
        mavenVersion = "";
      }
    }

    return mavenVersion;
  }

  public boolean isMavenVersion(String versionRange) {
    VersionScheme versionScheme = new GenericVersionScheme();

    if (versionRange == null) {
      throw new IllegalArgumentException("Version range must not be null");
    }
    if (StringUtils.isBlank(versionRange)) {
      throw new IllegalArgumentException("Version range must not be empty");
    }

    VersionConstraint constraint;
    try {
      constraint = versionScheme.parseVersionConstraint(versionRange);
    } catch (InvalidVersionSpecificationException e) {
      throw new IllegalArgumentException(e.getMessage(), e);
    }

    Version current;
    try {
      String mavenVersion = getMavenVersion();
      if (mavenVersion.length() <= 0) {
        throw new IllegalStateException("Could not determine current Maven version");
      }

      current = versionScheme.parseVersion(mavenVersion);
    } catch (InvalidVersionSpecificationException e) {
      throw new IllegalStateException("Could not parse current Maven version: " + e.getMessage(), e);
    }

    if (constraint.getRange() == null) {
      return constraint.getVersion().compareTo(current) <= 0;
    }
    return constraint.containsVersion(current);
  }

}
